Stem-mounted tire inflation pressure regulator

Abstract

The specification discloses a tire inflation pressure regulator facilitating precise tire inflation. The regulator includes a body, a two-position valve within the body, and a rotational lock. The body includes an air inlet, an air outlet, and an air vent. In one position, the valve directs air from the air inlet to the air outlet when the tire pressure is below a preset level; and, in a second position, the valve directs air from the air inlet to the air vent when the tire pressure exceeds the preset level to prevent overfilling. The valve moves rapidly between the two positions, and is unstable between the two positions. The valve includes a regulator enabling the preset level to be adjusted. The rotational lock enables the regulator to be screwed onto a tire stem, but prevents removal of the regulator from the tire stem without a key.

The invention claimed is: 
     
       1. A tire pressure regulator assembly comprising:
 a body assembly including an air inlet adapted to receive a conventional air nozzle and an air outlet adapted to connect to a conventional tire stem, the body assembly defining a vent port; 
 a two-position valve within the body assembly and including a flexible diaphragm supported by the body assembly, the valve having a first position directing air from the air inlet to only the air outlet, the valve having a second position different from the first position directing air from the air inlet to only the vent port, the valve being stable only in the first and second positions, the valve moving from the first position to the second position when the air pressure at the air outlet achieves a predetermined level, wherein the diaphragm is biased toward the first position and is responsive to air pressure at the air outlet to move the valve to the second position in a snap action when the air pressure achieves the predetermined level, wherein the two-position valve prevents the flow of air from the air outlet to the vent port in the first position and in the second position; and 
 an elongate guide defining an internal guide bore and an external guide surface, wherein: 
 air is directed through the internal guide bore and then to the air outlet when the valve is in the first position, and 
 air is directed along the external guide surface and then to the vent port when the valve is in the second position. 
 
     
     
       2. The tire pressure regulator assembly as defined in  claim 1  wherein the valve includes a spring urging the diaphragm to the first position, wherein the diaphragm is capable of overcoming the force of the spring and moving to the second position when the air pressure achieves the predetermined level. 
     
     
       3. The tire pressure regulator assembly as defined in  claim 1  wherein the valve includes a regulator for adjusting the predetermined level. 
     
     
       4. The tire pressure regulator assembly as defined in  claim 3  wherein the regulator includes a visual indicator identifying the predetermined level. 
     
     
       5. The tire pressure regulator assembly as defined in  claim 1  further comprising:
 a cap removably attached to the body assembly over the air inlet and the air vent to prevent the undesired loss of air therethrough; and 
 a seal on at least one of the body assembly and the cap adapted to provide an airtight seal therebetween. 
 
     
     
       6. The tire pressure regulator assembly of  claim 1  further comprising a compression seal adjacent the guide, wherein:
 the guide is spaced apart from the compression seal in the first position to allow air flow into the internal guide bore and then to the air outlet; and 
 the guide abuts the compression seal in the second position to allow air flow along the external guide surface and then to the vent port. 
 
     
     
       7. The tire pressure regulator assembly of  claim 1  wherein:
 the diaphragm is substantially planar; and 
 the diaphragm is responsive to air pressure at the air outlet to move from an unflexed position to a flexed position and thereby actuate the valve. 
 
     
     
       8. A tire pressure regulator assembly comprising:
 a body assembly including an air inlet adapted to receive a conventional air nozzle and an air outlet adapted to connect to a conventional tire stem, the body assembly defining a vent port; 
 a two-position valve within the body assembly, the two-position valve having a first position directing air from the air inlet to only the air outlet and a second position different from the first position directing air from the air inlet to only the vent port, the two-position valve being stable only in the first and second positions and moveable between the first and second positions in a snap action in response to air pressure at the air outlet, wherein the two-position valve prevents the flow of air from the air outlet to the vent port; and 
 an elongate guide defining an internal guide bore and an external guide surface, wherein: 
 air is directed through the internal guide bore and then to the air outlet when the valve is in the first position, and 
 air is directed along the external guide surface and then to the vent port when the valve is in the second position. 
 
     
     
       9. The tire pressure regulator assembly of  claim 8  wherein the valve includes a substantially planar diaphragm moveable between an unflexed position to a flexed position to thereby move the valve between the first and second positions. 
     
     
       10. The tire pressure regulator assembly of  claim 9  wherein the diaphragm is supported by the body assembly and flexes in a snap action to the flexed position when the air pressure at the air outlet achieves a predetermined level. 
     
     
       11. The tire pressure regulator assembly of  claim 9  further including a spring urging the diaphragm to the unflexed position, wherein the diaphragm is capable of overcoming the spring in the flexed position when the air pressure achieves the predetermined level. 
     
     
       12. The tire pressure regulator assembly of  claim 8  further including a compression seal adjacent the guide, wherein:
 the guide is spaced apart from the compression seal in the first position to allow air flow into the internal guide bore and then to the air outlet; and 
 the guide abuts the compression seal in the second position to allow air flow along the external guide surface and then to the vent port. 
 
     
     
       13. The tire pressure regulator assembly of  claim 8  wherein the valve includes a regulator for adjusting the predetermined level. 
     
     
       14. The tire pressure regulator assembly of  claim 13  wherein the regulator includes a visual indicator identifying the predetermined level. 
     
     
       15. The tire pressure regulator assembly of  claim 8  further comprising:
 a cap removably attached to the body assembly over the air inlet and the air vent to prevent the undesired loss of air therethrough; and 
 a seal on at least one of the body assembly and the cap adapted to provide an airtight seal therebetween.